Burner



June 20, 1944. o. CRAIG 2,351,928l 4 i BURNER Filed June 19, 1942 `3 Sheets-sheet 1 atto; wu i June 20, 1944.

O. CRAIG BURNER Filed June 1.9, 1942 5 Sheets-Sheet- 2 June zo, 1944. L Q CRAIG 2,351,928

BURNER Filed Junel 19, 1942 5 Sheets-Sheet 5 'ULL/soy CHHJG Patented June 20, 1944 BURNER@v n,

Ollison Craig, Worcester, Mass., assigner to `Riley Stoker Corporation, Worcester, Mass., a corporationof Massachusetts Application June 19, 1942, `Serial No. 447,623.`

This invention relates to burners, and more particularly to burners for use with fluent fuels, such as blast furnace gas, and having provision for introducing fuel and air into a furnace between spaced upright water wall tubes.

Blast furnace gas has a comparatively small heating value per unit volume, and it is therefore necessary to provide a large ilow area for the discharge of the gas into the furnace in order to avoid excessive gas velocities. Because of the obstruction afiorded'by'the water tubes, it is a difficult matter to provide the flow area required for large burner lcapacities. It is also very important to effect a thorough mixing of the fuel and air in order that combustion may take place f rapidly and a comparatively short flame may be obtained. Blast furnace gas usually carries a considerable quantity of solid'impurities in suspension, and when this material comes in contact with hot surfaces it adheres thereto. The removal of such deposited material from prior burners has been a serious problem.

It is accordingly one object of the invention to provide a burner which will be capable of discharging large volumes of fluent fuel and combustion air without excessivevelocity, particularly in connection with furnaces having water Wall tubes between which the fuel must pass. j

It is a further object of the invention to provide a burner which will produce a comparatively thorough mixing of the fuel and air elements enter the furnace'.

t is a further object of the invention to provide a Iburner constructed largely of metal'parts which are effectively shielded from the furnace heat by means of water tubes, n

It is a further object of the inventionto'provide a burner particularly suitable for use with blast furnace gas and so constructed that solid matter which may be deposited in the gas passages can be readily cleaned therefrom.

With these and other objects in View, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

as these Fig. l is a vertical section through a blast fur.-

nace gas burner, the section being `taken on the line I-I of Fig. 3; n 1

Fig. 2 is a section on the-line'Z-Z ofFig. 3; Fig. 3.is a section on'fthe line 3-3 of Fig. 1;

l Fig. 4. is an elevation of` the burner from the furnace side thereof, on a reduced scale;

, Fig. 5 is avsection on the line 5-,5 of Fig. l;

Fig. 6 is an enlarged fragmentary View in section on the line-B of Fig. 3;

Fig. '7 is a section von theline l-lof Fig. fi; and l Fig. 8 is a section-on lthe line-8&8 of Fig. .6.

The en'lboclimentl illustrated comprises va fur.-

nacewall II which is protected on the furnace .side by a row of spaced upright water wall tubes II. Y Water is circulated through these tubes in any-suitable manner so that they may serve to generate `steam by,the absorption of radiant heat 'from the furnace. The wall IIl is provided with .a rectangular opening I2 for 4.the receptioncf a "similarly shaped burner casing I4 which extends forwardly lfrom the wall` and -is preferably con structed largely of rolled -metal sheets orplates suitably welded together. The .portions` of the water tubes II which extendfacross the opening I2 are `arranged `in-groups, with two tubes in each group, so'V that the tubes arepositioned with alternately close and. wide spacing Yinv a common plane, asbest shown in. Fig. 3. Preferably the tubes'in each group are substantially, in contact with each other. In order that this may be done while maintaining a substantially uniform spacing of the tubes over the remainder of the wall I0; the requiredl tubesmay be formed withreverse'bends I5 above and below the burner opening "I2, `as shown inv FigMl. "Ihe rear portion of l the casing I4, whichis located within the opening lI2,'1'is lined with comparatively thick Icast plates I6 of a suitable heat-resisting metal. Preferably this portion of the casing-is offset outwardlyby an amount equal to the thickness of .the-'plates I6, so that the inner surfaces of the plates will be liush'v with vthe inner surfaces of the'casihg extending forwardly therefrom.

The interior of the casingv Hl is divided by meansof vertical 4longitudinally extending partitions I8 `and I9 to provide a series of air passages '2U-'and .gas passages ZI through which the elements of `combustion flow rearwardly and enter vthe furnace between the water tubes I.I. As best shown in Fig. 3,v each partition I8 is located in substantial alignment with onei group of the water tubes I I, while each partition I9 is loc-ated intermediate two of 'these groups. The air passages 20 alternate with the gas passages 2l, there being l'one air. .passage andr one` gas vpassage r discharging .between each pair ofad'jacent tube groups. The frontportions "of the partitions are formed of `rolled metal sheets-or plates with their top and bottom edges welded to the casing I4. The rear portions of the partitions I8 and |9 are formed of comparatively thick cast metal plates 23 and 24 respectively, of a suitable heat resisting metal. These plates are connected to the sheet metal with bolted ship-lap joints, with flush surfaces adjacent the gas passages 2|. As shown in Fig. 5, each of the plates23 and ,24 is made up of two sectionsy connected by a `ship-lap joint, to facilitate manufacture and assembly, and the top and bottom edges of the plates are fitted into grooves 25 in the plates I6. Gas is admitted to the fuel passages 2| through a gas inlet opening 26 in the bottom of the casing I4 near the front thereof, and air is admitted to the airpassages 20 through an air inlet opening 21 in the top of the casing near the front thereof. Both the gas and the air are preferably supplied at a pressure will begin to mix and combustion will start very shortly thereafter. This mixing will be greatly aided by the ffect of the deflectors 35, which will direct the adjacent streams into laterally converging paths. These deflectors are well protected from the furnace heat by means of the water tubes The various castings in the rear portion of the burner are well adapted `to withstand such heat' as is llikely, to reach them, and they can easily be replaced should occasion demand. The refractory material 30 will protect the walls 29 not only from the furnace heat but also from 'the heat of the combustion air, thereby minimizabove atmospheric, and the air is preferably pre- Y heated. The front end of each air passage 20 is separated from the gas inlet 26 therebeneath by an upwardly and forwardly sloping plate 29 which is lined on its rear face with refractory material 30. On `the front wall lof the casing I4 there are provided observation doors 32 aligned with the air passages 20 and cleanout doors 33 aligned with the gas passages 2|. 1

'I'he rear or discharge ends of the passages 20 and 2| are constructed to promote mixing vof the fuel and air. As shown particularly in Fig. 3, the rear edges yof the plates 24 are spaced for-- wardly from the row of water tubes so that the fuel and air streams may intermingle before they pass rearwardly between the water tubes. Thismixing is further promoted by means of rearwardly and laterally flaring deflectors 35 lo- I cated between the rear edges of the plates 23 and the water tubes to form rearward extensions of the partitions I8. These deflectors are preferably made of a suitable heat-resisting cast metal. and as shown in Figs. 6 and 'l they are fastened to the plates 23 by means oi bolts 36 which pass through rearwardly projecting lugs 31 on the plates, these lugs entering recesses 38`in'the deflectors. In the rear surface of each deflector 35 there is provided a vertical groove 40 for the reception of the forwardly projecting flanges 4I of T-shaped clips 42 (Figs. 6 and 8) which are welded to the water tubes II. Each flange 4| is provided with a vertical slot 43 therein foithe reception of -a transverse bolt 44 passing through the deflector 35. This construction maintains the desired relationship between the various parts withoutl interfering with longitudinal expansion of the water tubes. Y

It will be noted from Fig. 3 that the air'passages 2U are somewhat wider than the gas passagesl l2|. These relative widths are preferably so selected that the kinetic energy of the air flowing in a passage 20, as representedby one-half the product of its mass by the square of its`velocity,will be substantially equal to the kinetic energy of the gas flowing in an adjacent passage 2|. V This will avoid lateral deflection of the flames issuing into the furnace and ensure more effective mixing. l'n calculating the widths of these passages it will of coursebe necessary-to take into consideration not only the weights of air and gas required per unit of time for proper combustion, but also the temperatures and specific gravities cfthese elements.

It will now be apparent, that' in the operation of the inventionair and gas will flow rearwardly through the passages 20 .and 2| respectively,and as they pass the rear edges of vthe plates 24 :they

ing the deposit of material from the gas stream on the fronty of these Walls. Such deposits as 'form' within the gas passages 2| can readily be scraped off by suitable tools inserted through the doors 33. This procedure is facilitated by the smoothness of the gas passage walls and the lack of projecting parts. The burner construction, particularly the arrangement of the water tubes, is Ysuchas toprovide comparatively large areas for the discharge of air and fuelinto the furnace. Consequently high operating capacities can be obtained without the long flames resulting from excessive discharge velocities.

Having thusdescribed my invention, what I claim as new and desire to secure by Letters Patent is:

l. A burner for fluent fuel comprising a casing, a plurality of longitudinally extending parallel partitions dividing the interior of the casing into a` series of rearwardly directed passages, and means to supply fluent fuel to certain of the passages and combustion air to other `of thepassages, the fuel. passages alternating with the air passages, the rearedges of alternate partitions extending rearwardly a substantial distance beyond the rear edges of the intermediate partitions.

2. A burner for fluent fuel comprising a casing, a plurality of longitudinally extending parallel partitions dividing the interior of the casing into a series vof rearwardly directed passages, and means to supply fluentvfuel to certain ofthe passages and combustion air to other of the passages, the fuel passages alternating with the air passages, the rear edges of alternate partitions 4extending rearwardly a substantial distance beyond the rear edges of the intermediate partitions, and the rear portions of the said alternate partitions being shaped to deflect the adjacent lstreams laterally. 3. A burner for fluent fuel comprising a casing, a plurality of longitudinally extending upright partitions dividing the interior of the casing into a series of rearwardly directed passages, means to supply fluent fuel to certain of the passages and combustion air to other of the passages, the fuel passages alternating with the air passages, the rear edges of alternate partitions extending rearwardly a substantial distance beyond the rear edgesof the intermediate partitions, and a water wall tube adjacent the rear edge of each of said alternate partitionsA to shield the same from radiant heat. f

4. A burner for fluent fuel comprising a casing, aplurality of longitudinally extending parallel vpartitions dividing the interior of the casing into a series of passages, means to supply fluent fuel to certain of the passages and combustion air to yother of the passages,V the fuel passages alternating with the air passages, and rearwardly and laterally flaring deflectors adjacent the 'rear edges 0f alternate partitions and substantially aligned with the said alternate partitions to promote mixing of the issuing streams of fuel and air.

5. A burner for fluent fuel comprising a rectangular casing constructed largely of rolled metal sheets, a lining of comparatively thick cast plates of heat-resisting metal in the rear portion of the casing and shaped to provide a series of opposed longitudinal grooves, a plurality of longitudinally extending parallel partitions dividing the interior of the casing into a series of passages, the partitions having front portions of rolled metal sheets and rear portions of comparatively thick cast plates of heat-resisting metal which llt within the said grooves, and means to supply fluent fuel to certain of the passages and combustion air to other of the passages.

6. A burner for fluent fuel comprising a casing, a plurality of longitudinally extending upright partitions dividing the interior of the casing into a series of rearwardly directed passages, means to supply fluent fuel to certain of the passages and combustion air to other of the passages, water wall tubes located adjacent the rear edges of alternate partitions, and rearwardly and laterally flaring deflectors in front of the tubes.

7. A burner for fluent fuel comprising a casing, a plurality of longitudinally extending upright partitions dividing the interior of the casing into a series of rearwardly directed passages, means to supply fluent fuel to certain of the passages and combustion air to other of'the passages, water wall tubes located adjacent the rear edges of alternate partitions, rearwardly and laterally flaring dellectors in front of the tubes, and means connecting the deflectors to the tubes.

8. A burner for fluent fuel comprising a casing, a plurality of longitudinally extending upright partitions dividing the interior of the casing into a series of rearwardly directed passages, means to supply fluent fuel to certain of the passages and combustion air to other of the passages, water wall tubes located adjacent the rear edges of alternate partitions, rearwardly and laterally flaring deflectors in front of the tubes, clips welded to the front surfaces of the tubes, and means connecting the deilectors to the clips.

9. In combination with a furnace Wall having a rectangular opening therethrough, a row of spaced upright water wall tubes adjacent the furnace side of the Wall, certain of the tubes crossing the opening and being arranged in groups with two closely spaced tubes in eachgroup and wide spaces between the groups, a rectangular casing mounted in the opening and extending forwardly from the wall, upright partitions within the casing in substantial alignment with the tube groups, other upright partitions within the casing intermediate the first mentioned partitions with their rear edges spaced forwardly from the row of Water tubes, the partitions forming a pair of longitudinally extending passages leading to each of the said wide spaces, means to supply fluent fuel to one ofthe passages 1'n each pair, means to supply combustion air to the other passage in each pair, and a rearwardly and laterally flaring deilector mounted directly in front of each group of tubes t0 Dromote mixing of the fuel and air.

l0. In combination with a furnace wall having a rectangular opening therethrough, 'a row of spaced upright water wall tubes adjacent the furnace side of the wall, certain of the tubes crossing the opening and having reverse bends above and below the opening in the plane of the row to arrange the portions of the tubes adjacent the opening in groups with two closely spaced tubes in each group and wide spaces between the groups, a rectangular casing mounted in the opening and extending forwardly from the wall, upright partitions within the casing in substantial alignment with the tube groups, other upright partitions within the casing intermediate the rst mentioned partitions with their rear edges spaced forwardly from the row of water tubes, the partitions forming a series of longitudinally extending passages leading to the spaces between the tube groups, with two passages for each of the spaces, means to supply iluent fuel to certain of the passages and combustion air to other of the passages, the fuel passages alternating with the air passages, and a rearwardly and laterally flaring deflector mounted directly in front of each group of tubes to promote mixing of the fuel and air.

OLLISON CRAIG. 

